Lending standards aren’t getting looser; the market is changing.

That’s the findings from a study by the Urban Institute.

Study authors Jun Zhu, Laurie Goodman and Bing Bai say that market composition change explains the decrease in average credit scores for conventional and Federal Housing Administration mortgages.

Despite rising home prices, the mortgage lending rules have remained tight, inhibiting housing demand and economic growth, they say.

The price of FHA mortgages compared to agency loans with private mortgage insurance have driven would-be FHA borrowers to the GSEs, according to the report.

“Our analysis shows credit scores on conventional mortgages sold to government-sponsored enterprises like Fannie Mae and Freddie Mac averaged 752, down from 758 a year earlier. Credit scores on purchase loans backed by FHA declined even more, averaging 686, a 11-point drop down from 697,” the study says. “But pooling the loans together reveals that credit scores actually remained the same. The average credit score of all purchase loans stayed around 730 during the one-year period—no actual credit easing.”

The FHA is losing market share to private mortgage insurers, which provide insurance for GSE loans with loan to value ratio above 80. That lost share primarily consists of higher FICO borrowers.

“Credit standards aren’t declining. The credit score distribution for the market as a whole is largely unchanged. Most of the buzz about credit score declines in GSE and FHA loans are due to higher FICO score borrowers now choosing GSE lending over FHA—shifting the market share and reducing the credit scores of both,” the authors conclude.